Along with the development of ethernet technologies, ethernet plays more and more rolls in industrial circumstances. The benefit increase and operation stability of industrial production require the industrial ethernet to be more and more reliable. Therefore, the high availability of industrial ethernet attracts more and more attention.
At present, a commonly used ethernet system is the master-slave ring redundancy system, as shown in FIG. 1. In the ring redundancy system, the master switch 10 (the master apparatus) controls the operation of the whole network system, so as to ensure that the network is available when encountering a single fault (a single fault means that, the fault occurs in only one element among all switches and all network lines connecting the switches in the whole ring system). According to the master-slave ethernet system, each slave switch 20 is responsible for monitoring its own operation, and sending a fault alarm to the master switch when detecting a fault in it. The master switch sends a detecting message to the network in a time-setting way, monitors the operation of the network, processes the fault alarm from the slave switch, and determines a fault recovery action for the slave switch according to the fault alarm from the slave switch.
In the conventional master-slave ring redundancy system described above, for the reason that the master switch is responsible for the operation of the network and the recovery of the fault in a centralized way, network risks are highly converged on the master switch. If a fault occurs in the master switch, the network may be down, thus the reliability is low.